Spiders for brake assemblies of the foregoing type have been produced of weldable steel and formed by forging, stamping, casting or the like. The spider in its use on the brake assembly is welded to a stationery axle spindle of the vehicle on which the brake assembly is being utilized. The spider is elongated and serves as the foundation of the brake assembly. Even though the spider is not a moving part of the brake assembly, it is subject to and must withstand substantial stress under dynamic braking conditions. Also, the spider is subjected to substantial twisting forces as it transfers braking torque to the axle during braking.
The spider has heretofore traditionally been formed of steel as heavy cast or forged members with certain appropriate areas machined and bored to accommodate the brake assembly parts, such as the anchor pins and actuating camshaft, and for mounting the spider to the axle. The mounting is fixed by welding a hub of the spider on the axle. In heavy duty installations as in the case of trucks, truck trailers, and the like, the spider is a heavy duty, often massive and expensive part.
Several attempts in the prior art have been made to produce lighter weight spiders. U.S. Pat. Nos. 3,385,405 and 4,452,347 disclose the use of two plates secured together, and U.S. Pat. Nos. 4,200,174 and 4,337,851 disclose the use of a stamped brake spider U.S. Pat. No. 4,445,597 employs a stamped, sheet metal body part and a forged anchor pin piece. The patent coincidentally mentions a spider element comprised of a unitary casting or the like, of a weldable steel so as to provide for attachment to the vehicle axle by welding Traditionally, the brake spider of the type set forth in the prior art is made from readily weldable steel alloys.